////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1993-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if ! defined (octave_oct_hist_h)
#define octave_oct_hist_h 1

#include "octave-config.h"

#include <string>

#include "cmd-hist.h"

#include "ovl.h"

OCTAVE_NAMESPACE_BEGIN

  class interpreter;

  class OCTINTERP_API history_system
  {
  public:

    history_system (interpreter& interp);

    history_system (const history_system&) = delete;

    history_system& operator = (const history_system&) = delete;

    ~history_system (void) = default;

    void initialize (bool read_history_file = false);

    void write_timestamp (void);

    octave_value input_from_tmp_file (const octave_value_list& args,
                                      int nargout);

    bool input_from_tmp_file (void) const
    {
      return m_input_from_tmp_file;
    }

    bool input_from_tmp_file (bool flag)
    {
      return set (m_input_from_tmp_file, flag);
    }

    octave_value timestamp_format_string (const octave_value_list& args,
                                          int nargout);

    std::string timestamp_format_string (void) const
    {
      return m_timestamp_format_string;
    }

    std::string timestamp_format_string (const std::string& file)
    {
      return set (m_timestamp_format_string, file);
    }

    string_vector
    do_history (const octave_value_list& args = octave_value_list (),
                int nargout = 0);

    void do_edit_history (const octave_value_list& args = octave_value_list ());

    void do_run_history (const octave_value_list& args = octave_value_list ());

  private:

    interpreter& m_interpreter;

    // TRUE means input is coming from temporary history file.
    bool m_input_from_tmp_file;

    // The format of the timestamp marker written to the history file when
    // Octave exits.
    std::string m_timestamp_format_string;

    static std::string default_file (void);

    static int default_size (void);

    static std::string default_timestamp_format (void);

    template <typename T>
    T set (T& var, const T& new_val)
    {
      T old_val = var;
      var = new_val;
      return old_val;
    }
  };

OCTAVE_NAMESPACE_END

#endif
